AlQa'dah 27, 1436, Sep 11, 2015, SPA -- The suspected mastermind of last month's deadly bomb attack in Thailand left for China from Bangladesh 12 days ago, and efforts in Malaysia to track the man suspected of planting the explosives have been unsuccessful, Reuters cited Thai police as saying on Friday. No group has claimed responsibility for the Aug. 17 attack at a Hindu shrine in Bangkok, which killed 20 people, including 14 foreign tourists, among them seven from Hong Kong and mainland China. The man Thai police believe organised the plot and fled on the eve of the blast spent two weeks in Bangladesh before taking a flight from Dhaka to Beijing on Aug. 30, Bangladesh police said. "We checked his name, arrival date and passport number with the immigration department ... we found that it was correct and he left from the same airport (to Beijing)," A K M Shahidul Hoque, inspector general of Bangladesh police, told Reuters. Hoque said the name on the passport was Abu Dustar Abdulrahman, adding his men were looking for the suspect's hotel. In Beijing, Chinese Foreign Ministry spokesman Hong Lei said he was not aware if the suspect had flown to China from Bangladesh. "This case is still under investigation," he told a daily briefing. Thai police have ruled out international militants as responsible for the attack but have not said why nor what they believe the motive was. Thai police said on Friday the investigation had expanded to Malaysia.